A mounting tool for mounting an injector that injects fuel into an engine of a vehicle on a fuel pipe and a cylinder head of the engine is used (see Patent Document 1). Patent Document 1 discloses a clamp including right and left arm portions that are elastically brought into contact to be engaged with lateral sides of the injector, and a connecting portion that connects both of the arm portions. The arm portions of the clamp include three long holes and four slits in a direction perpendicular to the axial direction, and six beams in order to provide a predetermined elastic force to the clamp.